Electrostatic chucks are used to support substrates during processing. One function of an electrostatic chuck is to regulate a temperature of the supported substrate. To facilitate such temperature regulation, a surface of the electrostatic chuck that supports the substrate includes multiple surface features including mesas and a sealing band around a perimeter of the surface. During processing, a heat conductive fluid such as helium gas is pumped into an interface between the electrostatic chuck and the supported substrate. The sealing band seals the interface between the electrostatic chuck and the suspended substrate, preventing the heat conductive fluid from escaping. Over time, processing and cleaning of the electrostatic chuck erodes the surface features such as the sealing band and mesas, increasing their roughness, reducing a height of the mesas, and introducing leakage pathways. This introduces or increases a leakage rate of the fluid.